NOTE Macchi. Estimate of spawning frequency and batch fecundity of Cynoscion striatus 
377 
total length relationships obtained for both areas 
were compared with a test of equality of means and 
a test of equality of coefficients (Draper and Smith, 
1981 ). The relations of batch fecundity to total length 
and total weight (without ovary) were assessed with 
regression analysis (Draper and Smith, 1981). Sig- 
nificance of these relations were evaluated by test- 
ing if the slope of the regression was significantly 
different from zero. 
Results 
Oocyte diameter distributions of different maturity 
stages (immature to gravid) of C. striatus show that 
40 -i n=520 B 
25 100 175 250 325 400 475 550 625 700 
>* 
o 
c 
<D 
S' 
40 - f)=419 C 
25 100 175 250 325 400 475 550 625 700 
40 
30 
20 
10 
n = 182 
D 
illmm ■■■-■. 
I- 
25 100 175 250 325 400 475 550 625 700 
25 100 175 250 325 400 475 550 625 700 
Oocyte diameter (pm) 
Figure 2 
Oocyte diameter distributions for different maturity stages: 
A = immature; B = developing early; C = developing late; 
D = fully developed; and E = gravid. 
this species is a multiple spawner (Fig. 2). The gravid 
ovaries show four main groups of oocytes. The first 
group is composed mainly of primary growth oocytes 
(smaller than 100 pm). The second group is composed 
of partially yolked oocytes in several stages ranging 
approximately from 100 to 300 pm. The third group 
is formed by advanced yolked oocytes ranging be- 
tween 400 to 600 pm. The fourth group corresponds 
to the hydrated oocytes between 600 to 700 pm. 
During September, 95% of the females were found 
in the developing stages (early and late), with a small 
percentage (3%) in the fully developed phase (Fig. 
3). The samples obtained during early November 
were composed mainly of females in the partially 
spent stage with postovulatory follicles; about 11% 
of the samples were gravid females. These results 
indicate that the beginning of spawning of C. striatus 
in “El Rincon” is in October. 
Of the mature females taken in November, 12% 
had hydrated oocytes, 11% had new postovulatory 
follicles (phase 0), 13% had day-1 postovulatory fol- 
licles, and 11% had old postovulatory follicles (phase 
2) (Table 2). Therefore, each female was calculated 
to spawn every 7-9 days. The average of the per- 
centages of day-0 and day-1 spawning females was 
September 
60 
n =224 
40 
20 
II 
0 
g 
■ ■ _ - 
1 2 3 4 5 6 7 8 
>. 
o 
Q) 
ex 
<D 
November 
IL 
60 n 
40 
1 
20 - 
1 f-i 
_ _ ■ 1 ■ 1 
1 2 3 4 5 6 7 8 
Stages 
Figure 3 
Maturity-stage frequency of 
striped weakfish during Septem- 
ber 1995 and November 1994. 
Stages: 1 = immature; 2 = devel- 
oping early; 3 = developing late; 
4 = fully developed; 5 = gravid; 
6 = partially spent; 7 = spent; 
and 8 = 
resting. 
